JP7002845B2 - Tires with treads for low temperature performance and wet traction - Google Patents

Description

The present invention relates to a tire having a tread of rubber composition for promoting a combination of winter performance and wet traction. For such purposes, the tread rubber composition contains a combination of a low surface area precipitated silica reinforcing filler and a high softening point traction resin. Elastomers for tread rubber compositions include high cis 1,4-polybutadiene rubber and styrene / butadiene rubber.

Tires are sometimes desired to have treads to promote traction on wet surfaces. Various rubber compositions can be proposed for such tire treads.
For example, a tire tread rubber composition containing a high Tg (high glass transition temperature) diene synthetic elastomer with a high molecular weight may be desirable for such purposes, particularly wet traction (tire tread traction on wet road surfaces). .. Since such tire treads are desirable when the reinforcing filler is primarily precipitated silica, the reinforcing filler can be considered to be rich in precipitated silica.

In one aspect, the predicted wet traction performance of the tread rubber composition is based on maximizing the physical properties of its tan delta at about -10 ° C.
For such purposes, the tread rubber composition contains a high Tg elastomer that promotes wet traction of the tire tread so that the rubber composition promotes winter performance in cold climates, especially on snowy roads of vehicles. It is required to evaluate the provision of a tread rubber composition having low-temperature and low-rigidity physical properties.

In one embodiment, the predicted cold climate performance of the tread rubber composition is based on minimizing the physical properties of its stiffness at about -20 ° C (eg, minimizing the storage modulus G'at about -20 ° C).

So, the optimized (maximized) tandelta properties (for predicted wet traction performance) at about -10 ° C and the optimized (minimized) tread modulus (G'at about -20 ° C). ) Rigidity properties (to improve predicted cold climate performance), vehicle tire treads such as those having a rubber composition containing a combination of elastomers with high and medium glass transition temperatures (Tg). It is desirable to evaluate what you provide.

Providing tire tread rubber compositions that provide a combination of both wet traction and winter performance is considered to pose a major challenge.
It is recognized that concessions and adjustments will be required to achieve the task of providing such a balanced tread rubber performance to the tread rubber composition.

To deal with such challenges,
(A) Along with high content silica reinforcements containing precipitated silica of various surface areas (to assess their contribution to traction-promoting resin-containing treads).
(B) Traction-promoting resins at various softening points (to evaluate their assistance in promoting wet traction for treads containing high silica reinforcements).
It is also required to evaluate a rubber composition containing a combination of a precipitated silica filler reinforcing agent and a traction promoting resin.

In the description of the present invention, the terms "blended" rubber composition and "compound" are used to refer to a rubber composition that has been blended or blended with the appropriate rubber blending ingredients. The terms "rubber" and "elastomer" may be used interchangeably unless otherwise stated. The amount of material is usually expressed in parts of material (phr) per 100 parts by weight of rubber.

The glass transition temperature (Tg) of an elastomer can be determined by DSC measurement (differential scanning calorimetry) at a heating rate of about 10 ° C./min, as understood and well known to those skilled in the art. .. The softening point (Sp) of the resin can be determined by ASTM E28 (also known as a ring-shaped softening point measuring method).

According to the present invention, there is provided a pneumatic tire having a circumferential rubber tread for the purpose of ground contact. The tread is based on 100 parts by weight (phr) per elastomer:
(A) 100 phr conjugated diene-based elastomer, that is,
(1) cis 1,4-polybutadiene rubber of about 50 to about 10 phr (having a Tg in the range of about -90 ° C to about -110 ° C and a content of at least 95 percent isomer cis 1,4-).
(2) Conjugated diene-based elastomer containing about 50 to about 90 phr of styrene / butadiene elastomer (having a Tg in the range of about -65 ° C to about -55 ° C);
(B) Rubber reinforced filler of about 100 to about 200, or about 120 to about 180 phr, ie rubber reinforced carbon black and nitrogen (BET) surface area in the range of about 50 to about 110, or about 80 to about 100 m ² / g. Precipitated silica (amorphous synthetic precipitated silica) (where rubber reinforced carbon black is present in an amount of 1 phr or about 2 to about 15 phr), as well as a silica coupling agent for the precipitated silica (hydroxyl on the precipitated silica). A rubber reinforced filler that also contains a moiety that reacts with a group (eg, a silanol group) and another different moiety that interacts with the diene elastomer; and (C) a softening point in the range of about 110 ° C to about 170 ° C ( A traction-promoting resin of about 30 to about 70 phr with Sp) (eg, traction between the tread and the ground), ie a styrene-alphamethylstyrene copolymer resin having a softening point in the range of about 110 ° C to about 130 ° C. , Terpen-phenol resin with a softening point in the range of about 120 ° C to about 170 ° C, Kumaron-Inden resin with a softening point in the range of about 110 ° C to about 170 ° C, softening in the range of about 110 ° C to about 170 ° C. At least one of a petroleum hydrocarbon resin having dots, a terpen polymer resin having a softening point in the range of about 110 ° C to about 170 ° C, and a rosin-derived resin and copolymer having a softening point in the range of about 110 ° C to about 170 ° C. It is manufactured from a rubber composition containing a traction promoting resin containing.

In one embodiment, the traction-promoting resin comprises at least one of the styrene-alphamethylstyrene resin and the terpene-phenol resin.
In one embodiment, the styrene / butadiene elastomer has a styrene content in the range of about 10 to about 50 percent.

In one embodiment, the styrene / butadiene has a vinyl 1,2-content in the range of about 25 to about 35 percent based on its polybutadiene moiety.
In one embodiment, the styrene / butadiene elastomer is terminated with a functional group (eg, an alkoxy group and a thiol group) containing an alkoxy group and at least one of a primary amine group and a thiol group that reacts with the hydroxyl group on the precipitated silica. It is a functionalized styrene / butadiene elastomer and has a Tg in the range of about -65 ° C to about -55 ° C.

Further, according to the present invention, the tire tread is provided as a sulfur-cured rubber composition.
In one embodiment, the tread rubber composition further contains 25, or at least one additional diene-based elastomer up to about 15 phr. Such additional elastomers may include, for example, cis 1,4-polyisoprene (natural or synthetic rubber), and at least one copolymer of isoprene and butadiene.

In one embodiment, the precipitated silica and the silica coupling agent may be pre-reacted to form a complex thereof, and then added to the rubber composition.
In one embodiment, the precipitated silica and silica coupling agent can be added to the rubber composition and reacted in situ within the rubber composition.

As described above, the precipitated silica reinforcing agent may be characterized in that the BET surface area measured using, for example, nitrogen gas is in the range of about 50 to about 110, or about 80 to about 100 square meters per gram. .. The BET method for measuring surface area is described, for example, in Journal of the American Chemical Society (1938), Volume 60, and ASTM D3037.

Representative examples of rubber reinforced carbon black are listed, for example, in The Vanderbilt Rubber Handbook , 13th Edition, 1990, pages 417 and 418, along with their ASTM standards, but are not limited thereto. Such rubber reinforced carbon blacks can have iodine absorption values in the range of 60-240 g / kg and DBP values in the range of 34-150 cc / 100 g, for example.

Typical silica coupling agents for precipitated silica are, for example,
(A) Bis (3-trialkoxysilylalkyl) polysulfides (sulfur in the range of about 2 to about 4, or about 2 to about 2.6 or about 3.2 to about 3.8 in its polysulfide connecting bridge). Contains atoms), or (b) organic alkoxymercaptosilanes, or (c) combinations thereof.

Representatives of such bis (3-trialkoxysilylalkyl) polysulfides include bis (3-triethoxysilylpropyl) polysulfides.
In one embodiment, the styrene / alphamethylstyrene traction promoting resin is, for example, a relatively short chain copolymer of styrene and alphamethylstyrene. In one embodiment, such resins can be adequately produced, for example, by cation copolymerization of styrene and alpha-methylstyrene in a hydrocarbon solvent. Styrene / alpha-methylstyrene resins can have, for example, a styrene content in the range of about 10 to about 90 percent. The styrene / alpha-methylstyrene resin may have a softening point in the range of, for example, about 110 ° C to about 150 ° C, or about 110 ° C to 130 ° C. An example of a styrene / alpha-methylstyrene resin would be, for example, the Norsolene ^TM W120 manufactured by Cray Valley.

In one embodiment, the resin is a terpene-phenolic resin. Such a terpene-phenolic resin can be, for example, a copolymer of a phenolic monomer and a terpene, such as limonene and pinene. The terpene-phenolic resin may have a softening point in the range of, for example, about 110 ° C to about 170 ° C, or about 140 ° C to about 150 ° C. Examples of terpene-phenolic resins include, for example, Yasuhara Chemical Co., Ltd. It may be YS Polyester T145 manufactured by the same company.

In one embodiment, the resin is a kumaron-inden resin. Such a kumaron-inden resin contains kumaron and indene as monomer components constituting the resin skeleton (main chain), and is softened in the range of, for example, about 110 ° C to about 170 ° C or about 110 ° C to about 150 ° C. Can have points. Small amounts of monomers other than kumaron and indene, such as methylkumaron, styrene, alpha-methylstyrene, methylindene, vinyltoluene, dicyclopentadiene, cyclopentadiene, and diolefins (eg, isoprene and piperylene) may be incorporated into the skeleton. ..

In one embodiment, the resin is a petroleum hydrocarbon resin having a softening point (Sp), for example in the range of about 110 ° C to about 170 ° C. Such petroleum hydrocarbon resins can be, for example, aromatic and / or non-aromatic (eg, paraffinic) resins. Various petroleum resins are available. Some petroleum hydrocarbon resins have a low degree of unsaturation and a high aromatic content, but some may be highly unsaturated and some may not contain any aromatic structure. The difference in resin is mainly due to the olefin contained in the petroleum-based raw material from which the resin is derived. Conventional olefins for such resins are any C5 olefins (olefins and diolefins containing an average of 5 carbon atoms), such as cyclopentadiene, dicyclopentadiene, isoprene and piperylene, and any of them. C9 olefins (olefins and diolefins containing an average of 9 carbon atoms), such as vinyltoluene and alphamethylstyrene. Such resins may be made from a mixture of such C5 and C9 olefins.

In one embodiment, the resin is a terpene resin. Such resins may contain, for example, at least one polymer of limonene, alpha pinene and beta pinene and may have a softening point in the range of about 110 ° C to about 170 ° C, or about 110 ° C to about 160 ° C.

In one embodiment, the resin is a terpene-phenolic resin having, for example, a softening point in the range of about 120 ° C to about 170 ° C, or about 120 ° C to about 150 ° C. Such a terpene-phenolic resin can be, for example, a copolymer of a phenolic monomer and a terpene, such as limonene and pinene.

In one embodiment, the resin is a rosin-derived resin and its derivatives having a softening point (Sp) ranging from, for example, about 110 ° C to about 170 ° C. Representatives are, for example, gum rosin and wood rosin. Gum rosin and wood rosin have similar compositions, but the amount of rosin component can vary. Such resins can be in the form of esters of rosin and polyols such as pentaerythritol or glycols. In one embodiment, the resin may be at least partially hydrogenated (may be fully hydrogenated).

Those skilled in the art will readily know that the vulcanizable rubber composition will be formulated by methods commonly known in the field of rubber compounding. Further, the composition can also contain fatty acids, zinc oxide, waxes, antioxidants, ozone degradation inhibitors and deliquescent agents. As is known to those skilled in the art, the above additives are selected and commonly used in conventional amounts, depending on the intended use of the sulfur vulcanizable material and the sulfur-vulcanized material (rubber). Used for. Typical examples of sulfur donors are elemental sulfur (free sulfur), amine disulfides, polymeric polysulfides and sulfur olefin adducts. Usually, the sulfur vulcanizer is preferably elemental sulfur. The sulfur vulcanizer can be used, for example, in an amount in the range of about 0.5-8 phr, more preferably in the range of 1.2-6 phr. Typical amounts of processing aids (if used) for rubber compositions can include, for example, from about 1 to about 10 phr. A typical processing aid can be, for example, at least one of various fatty acids (eg, at least one of palmitic acid, stearic acid and oleic acid) or a fatty acid salt.

The rubber process oil can be used, if desired, in an amount of, for example, from about 10 to about 100, or from about 15 to about 45 phr, to assist in the processing of the uncured rubber composition. The process oil used may include both the extending oil present in the elastomer and the process oil added during the formulation. Suitable process oils include various petroleum oils known in the art such as aromatic oils, paraffin oils, naphthenic oils, and low PCA oils such as MES oils, TDAE oils, and heavy naphthenic oils. And various triglyceride-based vegetable oils such as sunflower oil, soybean oil, and safflower oil, especially soybean oil.

Typical amounts of antioxidants can include, for example, about 1 to about 5 phr. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine and others, such as those disclosed in The Vanderbilt Rubber Handbook (1978), pp. 344-346. Typical amounts of ozone degradation inhibitors can include, for example, about 1-5 phr. Typical amounts of fatty acids, when used, may be stearic acid and the like, but include from about 0.5 to about 5 phr. Typical amounts of zinc oxide can include, for example, about 2 to about 5 phr. A typical amount of wax comprises from about 1 to about 5 phr. Microcrystalline wax is often used. A typical amount of deafening agent, when used, can be used, for example, in an amount of about 0.1 to about 1 phr. Typical deafeners would be, for example, pentachlorothiophenols and dibenzamide diphenyl disulfides.

Sulfur vulcanization accelerators are used to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanized product. In one embodiment, a single accelerator system, i.e., a primary accelerator, may be used. The primary accelerator (s) can be used in total amounts, eg, in the range of about 0.5 to about 4, and sometimes preferably about 0.8 to about 2.5 phr. In another aspect, a combination of primary and secondary accelerators can be used to improve the properties of the activation and vulcanizer. In that case, the secondary accelerator is used in small amounts, for example in an amount of about 0.05 to about 4 phr. The combination of these accelerators is expected to have a synergistic effect on the final properties and is somewhat better than those produced using either accelerator alone. In addition, delaying accelerators that are not affected by standard processing temperatures but provide satisfactory curing at normal vulcanization temperatures can also be used. Vulcanization retarders can also be used. Suitable types of accelerators that can be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles, sulfenamides, and xanthates. In many cases, the primary accelerator is sulfenamide. When using a secondary accelerator, the secondary accelerator is often preferably guanidine, eg diphenylguanidine.

Mixing of vulcanizable rubber compositions can be achieved by methods known to those skilled in the art of rubber mixing. For example, the ingredients are typically mixed in at least two steps, i.e., at least one non-productive step followed by a productive mixing step. The final curing agent, including the sulfur vulcanizing agent, is typically mixed in the final stage. This stage is traditionally referred to as the "productive" mixing stage, where the mixing is typically at a temperature lower than or at the ultimate temperature of the previous non-productive mixing stage (s). It will be done. The terms "non-productive" and "productive" mixing stage are familiar to those skilled in the art of rubber mixing. The rubber composition may be subjected to a thermomechanical mixing step. The thermomechanical mixing step generally involves mechanical work in a mixer or extruder for a time appropriate to produce a rubber temperature in the range of 140 ° C. to 190 ° C., or about 140 ° C. to about 170 ° C. The appropriate time for thermomechanical work will vary depending on the operating conditions, as well as the volume and nature of the components. For example, thermomechanical work may range from 1 to 20 minutes, or about 4 to about 8 minutes.

The pneumatic tire of the present invention may be, for example, a passenger car tire, a truck tire, a racing tire, an aircraft tire, an agricultural tire, an earthwork machine tire, an off-road tire, or the like. Usually preferably the tires are passenger car or truck tires. The tire may be a radial ply tire or a bias ply tire, but a radial ply tire is usually preferable.

Vulcanization of pneumatic tires containing the tire tread of the present invention is generally carried out at conventional temperatures ranging from, for example, about 140 ° C to 200 ° C. In most cases, vulcanization is preferably carried out at a temperature in the range of about 150 ° C to 180 ° C. Any of the usual vulcanization methods such as heating in a press or a die, heating with superheated steam or hot air may be used. Such tires can be constructed, shaped, molded and cured by a variety of methods known to those of skill in the art and readily apparent.

The following examples are presented for purposes of explaining the present invention. It is not intended to be a limitation. Parts and percentages are parts by weight, usually parts by weight (phr) per 100 parts by weight of rubber, unless otherwise specified.

Example I
In this example, an exemplary rubber composition for a tire tread was produced and evaluated for use to promote a combination of wet traction and cold climate (winter) performance.

A control rubber composition was produced and used as a rubber sample A. The experimental rubber composition is a combination of a styrene / butadiene rubber having an intermediate Tg of about -60 ° C as a synthetic elastomer and a cis 1,4-polybutadiene rubber having a low Tg of about -106 ° C, as well as a traction resin and precipitated silica. It was produced as a precipitated silica reinforced rubber composition containing a silica coupling agent for rubber, and used as rubber samples B to E.

The rubber compositions are shown in Table 1 below.

¹ Goodyear Tire & Rubber Company Budene 1229 ^TM as a high cis 1,4-polybutadiene rubber. It has a Tg of about -106 ° C., a vinyl 1,2-content of less than about 4 percent and a cis 1,4-content of more than about 96 percent.

² Styrene / butadiene rubber (SSBR) is manufactured by organic solution preparation polymerization of styrene and 1,3-butadiene monomer. It has a styrene content of about 15 percent and a vinyl 1,2-content of about 30 percent (based on the polybutadiene moiety of SSBR), and a Tg of about -60 ° C. Obtained as Spritan SLR 3402 ^TM from Trinseo. The SSBR was a functionalized SSBR terminally functionalized with a functional group that is understood to contain alkoxy and thiol groups.

³ Copolymer of styrene and alpha-methylstyrene (styrene-alphamethylstyrene copolymer) as traction resin A. It has a softening point of about 80 ° C to about 90 ° C. Obtained as Sylvares SA85 ^TM from Arizona Chemicals.

⁴ Copolymer of styrene and alpha-methylstyrene as traction resin B (styrene-alphamethylstyrene copolymer). It has a softening point of about 110 ° C to 130 ° C. Obtained as Norsolene W120 ^TM from Total Petrochemicals.

⁵ Copolymer of terpene and phenol as traction resin C. It has a softening point of about 140 ° C to 150 ° C. Obtained as YS Polyester T145 ^TM from Yasuhara Chemical.

⁶ TDAE type petroleum oil as a rubber process oil.
⁷ As the precipitated silica X, ^HiSil315G -DTM manufactured by PPG. It has a BET (nitrogen) surface area of about 125 m ² / g.

⁸ Precipitated silica Y EZ090G-D ^TM manufactured by PPG. It has a BET (nitrogen) surface area of about 90 m ² / g.
Si266 ^TM manufactured by Evonik as a silica coupling agent containing ⁹ bis (3-triethoxysilylpropyl) polysulfide (containing an average of about 2 to about 2.6 linked sulfur atoms in the polysulfide bridge).

¹⁰ fatty acids (including stearic acid, palmitic acid and oleic acid).
¹¹ Sulfenamide primary accelerator and diphenylguanidine secondary accelerator as sulfur curing accelerators.

The rubber sample was produced by blending components other than the sulfur curing agent with a closed rubber mixer for about 4 minutes to a temperature of about 160 ° C. in the first non-productive mixing step (NP1). The resulting mixture was then individually mixed in a closed rubber mixer to a temperature of about 140 ° C. in a continuous second non-productive mixing step (NP2). The rubber composition was then mixed with a sulfur curing agent (including sulfur and a sulfur curing accelerator) in a closed rubber mixer in the productive mixing step (P) for about 2 minutes to a temperature of about 115 ° C. The rubber composition was removed from the closed mixer after each mixing step and cooled to less than 40 ° C. between each individual non-productive mixing step and before the final productive mixing step.

Table 2 below shows the various physical properties of the rubber composition based on the basic formulation of Table 1 (here reported as Control Rubber Samples A and Experimental Rubber Samples B-E). When reported for hardened rubber samples such as stress-strain, hot rebound and hardness values, the rubber samples were hardened at a temperature of about 170 ° C. for about 10 minutes.

A tangent delta (tan delta) test was performed at -10 ° C to determine the predicted wet traction.
In order to obtain the predicted low temperature (winter snow road) performance, a rubber rigidity test (storage elastic modulus G') was carried out at −20 ° C., and the rigidity value of the compound (rubber composition) at a low operating temperature was obtained.

Findings from Table 2
Consideration of wet traction-tan delta (-10 ° C) and cold climate performance-G'(-20 ° C)
(A) Experimental rubber samples B and C using the same amount of the same traction resin (styrene-alphamethylstyrene copolymer) as the control rubber sample A, but substantially low surface area precipitated silica was used. Used (BET nitrogen surface area is 90 m ² / g, whereas the BET surface area of the precipitated silica of control rubber sample A is 125 m ² / g).

The rolling resistance prediction characteristics (proven by tan delta at 50 ° C.) of tires with treads of each rubber composition were beneficially reduced in tan delta values in experimental rubber samples B and C and maintained in experimental rubber samples D and E. It has been beneficially improved or maintained in the sense that it has been.

At the same time, the winter (low temperature) performance of the experimental rubber samples B and C was also improved (the aforementioned predicted rolling resistance was also improved, as evidenced by the desirable reduction in storage modulus G'at -20 ° C. While).

However, the wet traction prediction properties of the experimental rubber samples B and C were reduced in the sense that the tan delta at −10 ° C. was undesirably reduced compared to the control rubber sample A.

(B) Use of traction resin having high softening point The experimental rubber samples D and E used the same low surface area precipitated silica as the experimental rubber samples B and C (BET nitrogen surface area is the BET of the precipitated silica of the control rubber sample A). The surface area is 125 m ² / g, whereas it is 90 m ² / g).

However, both the experimental rubber samples D and E have significantly higher softening points than the traction resins used in the rubber samples A and the experimental rubber samples B and C, which have a substantially lower softening point of 85 ° C. (120, respectively). ° C. and 145 ° C.) were used.

Specifically, the experimental rubber sample D used a styrene-alpha-methylstyrene copolymer having a softening point of 120 ° C., and the experimental rubber sample E used a terpene / phenol copolymer having a softening point of 145 ° C.

It can be concluded that the experimental rubber samples D and E provided better wet traction properties than the control rubber sample A due to the combination of the high amount of low surface area precipitated silica and the high softening point traction promoting resin. At the same time, the winter (low temperature) characteristics of the experimental rubber samples D and E are unexpectedly better than the control rubber samples A, and thus a newly discovered predictive improvement is also obtained.

Furthermore, it can be concluded that the rolling resistance prediction characteristics of the experimental rubber samples D and E are also beneficially maintained as compared with the control rubber samples A.
Although certain representative embodiments and details have been shown for purposes of illustrating the invention, those skilled in the art will appreciate that various changes and modifications can be made therein without departing from the spirit or scope of the invention. It will be obvious.

[Aspects of the invention]
1. 1. A pneumatic tire with a circumferential rubber tread intended for ground contact, wherein the tread is based on 100 parts by weight of parts by weight (phr) per elastomer:
(A) 100 phr conjugated diene-based elastomer, that is,
(1) cis 1,4-polybutadiene rubber of about 50 to about 10 phr (having a Tg in the range of about -90 ° C to about -110 ° C and a content of at least 95 percent isomer cis 1,4-).
(2) Conjugated diene-based elastomer containing about 50 to about 90 phr of styrene / butadiene elastomer (having a Tg in the range of about -65 ° C to about -55 ° C);
(B) A rubber reinforced filler of about 100 to about 200 phr, ie rubber reinforced carbon black and settling silica having a nitrogen surface area in the range of about 50 to about 110 m ² / g (where the rubber reinforced carbon black is 1 phr or about 2). Along with (present in an amount of ~ about 15 phr), a silica coupling agent for the precipitated silica (having a moiety that reacts with the hydroxyl group on the precipitated silica and another different moiety that interacts with the diene elastomer). A rubber reinforcing filler containing; and (C) a traction-promoting resin of about 30 to about 70 phr (having a softening point (Sp) in the range of about 110 ° C to about 170 ° C), ie, in the range of about 110 ° C to about 130 ° C. A styrene-alphamethylstyrene copolymer resin having a softening point, a terpene-phenol resin having a softening point in the range of about 120 ° C. to about 170 ° C., a kumaron-inden resin having a softening point in the range of about 110 ° C. to about 170 ° C., A petroleum hydrocarbon resin having a softening point in the range of about 110 ° C. to about 170 ° C., a terpene polymer resin having a softening point in the range of about 110 ° C. to about 170 ° C., and a softening point in the range of about 110 ° C. to about 170 ° C. A pneumatic tire made from a rubber composition comprising a rosin-inducing resin and a traction-promoting resin comprising at least one of the copolymers.

2. 2. 1. The tire according to 1, wherein the traction promoting resin contains at least one of the styrene-alphamethylstyrene resin and the terpene-phenol resin, particularly a styrene-alphamethylstyrene resin.

3. 3. 1. The tire according to 1, wherein the styrene / butadiene elastomer has a styrene content in the range of about 10 to about 20 percent.
4. 1. The tire according to 1, wherein the styrene / butadiene has a vinyl 1,2-content in the range of about 25 to about 35 percent based on its polybutadiene moiety.

5. The tire according to 1 above, wherein the styrene / butadiene elastomer has a styrene content in the range of about 10 to about 20 percent and a vinyl 1,2-content in the range of about 25 to about 35 percent based on the polybutadiene moiety thereof.

6. 1. The styrene / butadiene elastomer is a styrene / butadiene elastomer end-functionalized with a functional group containing at least one of an alkoxy and a primary amine and a thiol group that reacts with the hydroxyl group on the precipitated silica. tire.

7. 5. The tire according to 5, wherein the styrene / butadiene elastomer is a styrene / butadiene elastomer end-functionalized with a functional group containing an alkoxy and a thiol group.
8. The tire according to 1. The tire according to 1.

9. The tire according to 1. The tire according to 1, wherein the precipitated silica and the silica coupling agent are added to the rubber composition and reacted with each other in situ in the rubber composition.
10. The silica coupling agent
(A) Bis (3-trialkoxysilylalkyl) polysulfide (containing an average of about 2 to about 4 sulfur atoms in its polysulfide connecting bridge), or (b) organic alkoxymercaptosilane, or (c). The tire according to 1, which comprises a combination thereof.

11. 1. The tire according to 1, wherein the silica coupling agent contains a bis (3-triethoxysilylpropyl) polysulfide.
12. The tire according to 1 above, wherein the silica coupling agent contains a bis (3-triethoxysilylpropyl) polysulfide (containing about 2 to about 2.6 sulfur atoms on average in the polysulfide bridge).

13. 1. The tire according to 1, wherein the silica coupling agent contains an organic alkoxymercaptosilane.
14. The tire according to 1, wherein the traction promoting resin is the Kumaron-inden resin.

15. 1. The tire according to 1, wherein the traction promoting resin is the petroleum hydrocarbon resin.
16. 1. The tire according to 1, wherein the traction promoting resin is the terpene polymer resin.

17. 1. The tire according to 1, wherein the traction promoting resin is the rosin-inducing resin.
18. 17. The tire according to 17, wherein the rosin-inducing resin is at least partially hydrogenated.
19. The tire according to 1, wherein the tread rubber composition is sulfur-cured.

20. 5. The tire according to 5, wherein the tread rubber composition is sulfur-cured.

Claims (20)

A pneumatic tire with a circumferential rubber tread for ground contact.
The tread is based on 100 parts by weight of parts by weight (phr) per elastomer.
(A) A 100 phr conjugated diene-based elastomer, wherein the conjugated diene-based elastomer is
(1) cis 1,4-polybutadiene rubber having a Tg in the range of −90 ° C. to −110 ° C. and at least 95% isomer cis 1,4-content of 50 to 10 phr, and (2) 50 to 90 phr. , Includes styrene / butadiene elastomers with Tg in the range -65 ° C to -55 ° C;
(B) 100-200 phr rubber reinforced filler, wherein the rubber reinforced filler is present in an amount of 1 phr or 2-15 phr, rubber reinforced carbon black.
For settling silica having a nitrogen surface area in the range of 50-110 m ² / g, and a moiety that reacts with the hydroxyl group on the precipitated silica and another different moiety that interacts with the diene elastomer. Includes a silica coupling agent; and (C) a traction-promoting resin having a softening point (Sp) in the range of 110 ° C. to 170 ° C., wherein the traction-promoting resin is at 110 ° C. to 130 ° C. Styrene-alphamethylstyrene copolymer resin with softening points in the range, terpene-phenolic resin with softening points in the range of 120 ° C to 170 ° C, kumaron-inden resin with softening points in the range of 110 ° C to 170 ° C, 110 ° C. Derived from rosin, which has a softening point in the range of ~ 170 ° C, a terpene polymer resin having a softening point in the range of 110 ° C to 170 ° C, and a softening point in the range of 110 ° C to 170 ° C. A pneumatic tire made from a rubber composition comprising at least one of a resin and a derivative thereof. The tire according to claim 1, wherein the traction promoting resin contains at least one of the styrene-alphamethylstyrene resin and the terpene-phenol resin. The tire according to claim 1, wherein the styrene / butadiene elastomer has a styrene content in the range of 10 to 20 percent. The tire according to claim 1, wherein the styrene / butadiene has a vinyl 1,2-content in the range of 25 to 35 percent based on its polybutadiene moiety. The first aspect of the invention is characterized in that the styrene / butadiene elastomer has a styrene content in the range of 10 to 20 percent and a vinyl 1,2-content in the range of 25 to 35 percent based on the polybutadiene moiety thereof. The tires listed. The styrene / butadiene elastomer is a styrene / butadiene elastomer end-functionalized with a functional group that reacts with a hydroxyl group on the precipitated silica, and the functional group is an alkoxy group and at least one of a primary amine group and a thiol group. The tire according to claim 1, wherein the tire comprises. The tire according to claim 5, wherein the styrene / butadiene elastomer is a styrene / butadiene elastomer end-functionalized with a functional group containing an alkoxy group and a thiol group. The method for producing a rubber composition of a rubber tread according to claim 1, which comprises blending (A), (B) and (C), wherein the precipitated silica and a silica coupling agent are preliminarily reacted. A method comprising adding them to a rubber composition after forming their composite. The method for producing a rubber composition of a rubber tread according to claim 1, which comprises blending (A), (B) and (C), wherein the precipitated silica and a silica coupling agent are used as a rubber composition. A method comprising adding to and reacting with each other in situ in a rubber composition. The silica coupling agent
( A ) Bis (3-trialkoxysilylalkyl) polysulfides (containing an average of 2-4 sulfur atoms in their polysulfide connecting bridges), or ( b ) organic alkoxymercaptosilanes, or ( c ) theirs. The tire according to claim 1, wherein the tire includes a combination. The tire according to claim 1, wherein the silica coupling agent contains a bis (3-triethoxysilylpropyl) polysulfide. The first aspect of the present invention, wherein the silica coupling agent contains a bis (3-triethoxysilylpropyl) polysulfide (containing an average of 2 to 2.6 sulfur atoms in the polysulfide bridge). tire. The tire according to claim 1, wherein the silica coupling agent contains an organic alkoxymercaptosilane. The tire according to claim 1, wherein the traction promoting resin is the Kumaron-inden resin. The tire according to claim 1, wherein the traction promoting resin is the petroleum hydrocarbon resin. The tire according to claim 1, wherein the traction promoting resin is the terpene polymer resin. The tire according to claim 1, wherein the traction promoting resin is a resin derived from the rosin. The tire according to claim 17, wherein the resin derived from rosin is at least partially hydrogenated. The tire according to claim 1, wherein the tread rubber composition is sulfur-cured. The tire according to claim 5, wherein the tread rubber composition is sulfur-cured.